I'm about to embark on my first (hopefully last) Miata part-out. I've removed almost everything on a Miata at some point, so most of the work should be somewhat familiar. Unfortunately the part-out will occur off-road (ie. in the dirt), so I don't have the luxury of rolling the car around once I get started, or using a cherry picker, for that matter. Any advice that can help make this less of a pain in the ass?

The first stage in the process will be the interior removal. Mostly straight forward, not too much to worry about. The rear end will have to come up and back wheels off, in order to remove the rollbar. My questions at this stage:
Regarding stability of the jacks and jack stands. Should I grab some concrete pavers to place under the jack stand feet, to keep them from digging in to the ground?
Is there anything else I can do to make getting under the car easier? I could park the car on a tarp, or buy a sheet of plywood.
Should I drain and remove the gas tank? I would assume that you can not scrap a car full of fuel.
Are there interior parts on the car that just will never sell, that I should just scrap (steering column, heater core, etc)? I don't want to hang on to a bunch of crap.

The second stage of the process will be finishing the car off. I just plan on hauling the body off to the Recycling plant down the street.

In this instance, is it going to be easier to cut the front clip off of the car to remove the engine/tranny?
Do I need to worry about pulling the windshield?
How high does the car need to be to get everything out from underneath it?
What are my scrap-able items (subframe, PPF, exhaust, shell, glass)?

Am I missing anything else that will make my job quicker/easier?